> But I cannot use mount_mfs() simply becouse I do not have any swap
> (or other writable) partition on disk.  So I'm try to use md.

Not having any swap does not, in itself, prevent you from using mfs.
No swap means your total memory consumption - including mfs "disk" -
cannot exceed your real RAM, but that's all.  I've used mfs on swapless
systems often enough myself.

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